Fluid vane motor

ABSTRACT

A FLUID MOTOR HAVING A ROTATABLE OUTER RING AND A STATIONARY INNER CAM MEMBER. A PLURALITY OF VANES ARE SLIDABLY DISPOSED IN THE RING MEMBER AND EXTEND INWARDLY THEREFROM INTO FLUID CHAMBERS FORMED BETWEEN THE RING AND CAM. A FLUID OPERATED PISTON WITH DIFFERENTIAL AREAS ON THE ENDS IS ASSOCIATED WITH EACH VANE MEMBER SUCH THAT THE PRESENCE OF FLUID PRESSURE TO DRIVE THE MOTOR OPERATES ON THE PISTON TO MOVE THE VANES INWARDLY TO ENGAGE THE SURFACE OF THE CAM THUS FORMING CLOSED FLUID CHAMBER BETWEEN THE RING AND THE CAM.

July 4, 1972 R p RQHDE EIAL 3,674,385

FLUID VANE MOTOR Filed Aug. 28, 1970 W gamma 6 jfij fjga ,QT O /VEV United States Patent 3,674,385 FLUID VANE MOTOR Robert P. Rohde, Saginaw, Clarence E. Welsh, Merrill, and Hans Engelhardt, Saginaw, Mich., assignors to General Motors Corporation, Detroit, Mich. Filed Aug. 28, 1970, Ser. No. 67,752 Int. Cl. F01c 1/00; F03c 3/00 US. Cl. 418-177 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to vane type fluid motors and more particularly to vane type fluid motors in which the vanes are retracted to reduce energy losses when the motor is freewheeling.

Fluid motors have been proposed in wheel drive systems to provide an auxiliary fluid drive at the wheels, for example, the front wheels of a passenger vehicle during selected periods of operation. However, when the fluid drive is not being used the fluid motor should be effectively removed from the drive system to improve the vehicle efficiency. 'In the past this has been accomplished by connecting the fluid motor to the wheel through a fluid operated clutch or a one way clutch which is released when the motor is inoperable. The present invent-ion eflectively removes the fluid motor from the drive system by retracting the vanes from the fluid chambers of the motor to prevent pressure from developing within the fluid motor.

In the present invention each of the vanes in the motor are operatively connected, through a lost motion device, 1

with a fluid operated piston which is spring biased to move the vanes outwardly out of contact with a cam surface when drive pressure is not supplied to the motor. However, when fluid drive pressure is suplied to the motor, the supply pressure also acts on the differential area of the piston to move the piston inwardly whereby the lost motion device between the piston and the vane will cause the vane to move into contact with a central cam surface. When the vanes are in contact with the cam surface a plurality of pressure chambers are formed between the cam surface and the ring so that fluid pressure admitted to the chambers will act on the vane to cause the vanes and ring to rotate about the cam surface.

It is, therefore, an object of this invention to provide in a fluid vane motor a plurality of vanes slidably disposed in an outer rotatable ring member and a plurality of fluid pistons operatively connect with the vanes to urge the vanes into engagement with an inner stationary cam surface when fluid pressure is supplied through the motor.

This and other objects and advantages of the present invention will be apparent to those skilled in the art from the following description and drawings in which:

FIG. 1 is a cross-sectional elevational view;

FIG. 2 is a partial sectional view taken along line 22 of FIG. 1.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1.

Referring to the drawings wherein like characters designate like or corresponding parts there is shown a spindle ice 10 secured to a bracket 12 which is part of a vehicle steering system.

A housing 14 is rotatably mounted on the spindle 10 by a tapered roller bearing 16 which housing 14 has a brake disc 18 adapted to be used with a disc brake. A wheel mounting cover 20 is secured to the housing 14 to form an annular cavity 21. A plurality of fasteners 22 are secured in the cover 20 and are adapted to permit mounting of a drive wheel on the housing 14. The cover 20 is also rotatably mounted on the spindle 10 through a tapered roller bearing 24. The housing 14 and cover 20 are positioned on the spindle 10 by a nut 26 which is threaded onto the spindle 10. A washer 28 positioned between a nut 26 and the bearing 24 forces the bearing 24 against a shoulder 30 on the cover 20 and the bearing 16 against the shoulder 32 on the bracket 12 thus preventing linear motion of the housing 14. A cap 34 secured to the cover 20 by a plurality of fasteners 36 covers the end of the spindle 10 and cooperates with a sealing ring 38 to prevent fluid leakage from the outboard end of the spindle 10. A lip seal 40 is press fitted in the brake disc 18 and positioned by a retaining ring 42 to prevent fluid leakage between the housing 14 and the bracket 12.

A ring 44 is positioned in the cavity 21 and secured to the housing 14 by a plurality of fasteners extending through openings 23 in the cover 20 and openings 25 in ring 44 into the housing 14 and located radially in the housing 14 by a plurality of pins 46 while a cam member 48 is operatively connected with the spindle 10 through a spline 50, which allows the cam 48 to float in cavity 21. The ring 44 has a circular inner diameter 52 circumjacent a three lobe cam surface 54 on the cam 48. Three fluid chambers 56 are formed between the ring 44 and the cam 48 due to the three lobe configuration of the cam 48.

A plurality of vanes 58 are slidably disposed in the ring 44. The vanes 58 are secured to a pin 60 through a threaded connection 62. The pin 60 has an enlarged head 64 which extends into a cavity 66 in a piston 68 which is slidably disposed in a chamber 70 in the ring 44 and sealed with a O ring 69. It is also slidably disposed in a smaller diameter 71 in the ring and sealed with a spool seal. The pistons 68 and the chambers 70 cooperate to form a plurality of linear fluid motors. A washer 72 surrounds the stem of the pin 60 and is held in position against a shoulder 74 on the piston 68 by a compression spring 76 compressed between the washer 72 and a shoulder 78 on the ring 44. A second compression spring 80 is mounted circumjacent the stem of the pin 60 and is compressed between the vane 58 and the washer 72. The spring 80 and the pin 60 cooperate to provide lost motion connections between the pistons 68 and the vanes 58.

The cam 48 has three ports 82 open to thecam surface 54 and in fluid communication via passageway 84 with an inner port 86 circumjacent the spindle 10. The came also has three ports 88 open to the cam surface 54 and in fluid communication via passageways 90 with an inner port 92 circumjacent the spindle 10 and axially displaced from the inner port 86. A seal ring 94 on the spindle 10 prevents fluid leakage between the ports 86 and 92 While a pair of seal ring 96 and 98 prevent fluid leakage from the ports 86 and 90 to the housing 14 along the spindle 10. The port 86 is in fluid communication with a fluid passage 100 in the spindle 10 and the port 92 is in fluid communication with a passage 102 in the spindle 10. These passageways 100 and 102 are adapted to be connected with a fluid source, not shown, to permit fluid pressure to be directed through the ports 82 and 88 to provide fluid pressure to drive the motor. Seals 103 and 105 at both ends of the cam 48 prevent fluid leakage from cavities 56 to areas in the housing at both ends of spindle 10.

As seen in FIG. 3 the passageway 102 and 100 are in fluid communication via ball check valves 104 and 106 respectively with a fluid port'108 formed in the housing 14- The port 108 is in fluid communication with a chamber 110 in the housing 14 through a passageway 112 and a passageway 114. The ball check valve 104 and 106 function such that the higher pressure of passageways 102 and 100 is directed to the port 108 and through the passageways 112 and 114 to the chamber 110. The pressure in the port 108 closes the check valve 104 or 106 to the lower pressure passage. For example, if fluid pressure is supplied to the motor through the passageway 100, the fluid pressure passes through the ball check 106 to the port 108 and the downstream side of valve 104. The pressure on the downstream side of valve 104 will cause the check valve to seat to prevent fluid communication between passageways 100 and 102. A pair of seal rings 109 and 111 prevent fluid leakage from port 108 to the housing along the spindle 10. To reduce the loading on vanes 58 openings 115 and 117 in the vanes 58 allow fluid to pass through resulting in the same pressure on both top and bottom of vanes 58 so the only load pushing the vanes 58 against the cam 48 is due to compression spring 80. Fluid through the openings 115 and 117 in the vanes also pressurizes the small end of the pistons 68.

The chamber 110 is circumjacent the ring 44 and is in fluid communication with each of the chambers 70. Thus, when the chamber 110 is pressurized the chambers 70 will be pressurized so that the pistons 68 because of the diiferential areas will be urged inwardly to act on the vanes 58 through the springs 80 to cause the vanes 58 to engage the cam surface 54. Fluid from the cavity formed between the sealing areas is vented to the low pressure side of the motor through passage 113. When the chamber 110 is exhausted, for example when fluid pressure is not present at either passageway 100 or 102, the pistons 68 will be moved radially outward into chamber 70 by the spring 76. Fluid will flow from the low pressure side of the motor into the cavity formed between the sealing areas. As the pistons 68 move outwardly the washers 72 will engage the head 64 of the pins 60 to move the vanes radially outward away from the cam surface 54. When high pressure is present in passageway 100 and low pressure or motor discharge fluid is present in passageway 102 the fluid pressure will enter port 82. The fluid pressure in port 82 is communicated with the fluid chamber 56 to act on one side of the vanes 58. The other side of some of the vanes 58 is open to discharge pressure through ports 88 which are in fluid communication with passageway 102. The pressure in chamber 56 admitted through port 82 will cause the ring 44 to rotate in a clockwise direction as viewed in FIG. 2. If high pressure is admitted to passageway 102 and discharge pressure is conducted through passageway 100, the high pressure will act through ports 88 to the chamber 56 and consequently on the vanes 58 to cause the ring 44 to rotate in a counter clockwise direction. Thus, the motor may be operated in both clockwise and counterclockwise directions for forward and reverse travel in a vehicle. When both passageways 100 and 102 are connected to exhaust and the housing 14 and the ring 44 are driven by the vehicle wheel, the vanes 58 are retracted from the chambers 56, as described above, to permit fluid communication between ports 82 and 86 thereby preventing fluid pressure from developing in the chambers 56. Since fluid pressures cannot be developed in the chambers 56 the fluid motor will freewheel with very little energy loss.

The ports 86 and 92 are in fluid communication via passageways 116 and 118 and check valves 120 and 122 respectively with the left end of the spindle 10. The check valve 120 or 122 prevent high pressure in port 86 or 92 from escaping through the left end of the spindle while the check valve 122 or 120 connected to the low pressure port prevents excess pressure buildup in the area in the left end of the spindle 10. Fluid from bearing and seal area at right end of spindle 10 is vented to area at left end of spindle 10 through passages 119 and 121 and check valves and 122 thereby preventing pressure build-up. These check valves 120 and 122 also facilitate free transfer of fluid between ports 92 and 86 when the fluid motor is freewheeling.

Obviously, many modifications and variations of the present invention are possible in light of the above teaching. It is, therefore, to be understood that Within the scope of the appended claims the invention may be practiced otherwise than specifically described.

What is claimed is:

1. A fluid motor for selectively providing'driving and freewheeling operation comprising a driving housing; ring means secured to said housing; spindle means for rotatably supporting said housing; cam means operatively connected with'said spindle means; piston means slidably disposed in said ring means; vane means slidably disposed in said ring means and being operatively connected with said piston means; and lost motion means operatively connected between said piston means and said vane means for permitting relative motion therebetween including pin means secured to said vane means and springs means resiliently urging said piston means into contact with said pin means; said piston means being selectively pressurized to urge said vanes into contact with said cam means during driving operation and unpressurized to permit said vanes to move out of contact with said cam means during freewheeling operation.

2. A fluid motor for selectively providing driving and freewheeling operation comprising a driving housing; ring means secured to said housing; spindle means for rotatably supporting said housing; cam means operatively connected with said spindle means; piston means slidably disposed in said ring means; spring means operatively connected between said piston means and said ring means; vane means slidably disposed in said ring means; and lost motion means operatively connecting said piston means and said vane means; said piston means being selectively pressurized to urge said vanes into contact with said cam means during driving operation and unpressurized to permit said spring means to move said vanes out of contact with said cam means during freewheeling operation.

3. A fluid motor comprising rotatable housing means; ring means secured to said housing; spindle means rotatably supporting said housing; cam means operatively connected with said spindle means and being disposed circumjacent within said ring means and cooperating therewith to form fluid chamber means; a plurality of passage means in said spindle means and said cam means for supplying fluid to and directing fluid from said chamber means; piston means slidably disposed in said ring means in fluid communication with said passage means being movable radially in said ring means in response to fluid pressure in said passage means; vane means slidably disposed in said ring means adjacent to and being operatively connected with said piston means for movement into said fluid chamber means when said piston means are pressurized; lost motion means operatively connected between said piston means and said vane means for permitting relative motion therebetween when said piston means is pressurized; and spring means operatively connected between said ring means and said piston means being operatively connected with said lost motion means for moving said piston means and said vane means radially in said ring means when said passage means are unpressurized for moving said vane means out of said fluid chambers to prevent pressure development in said fluid chambers.

4. A fluid motor comprising rotatable housing means; ring means secured to said housing; spindle means rotatably supporting said housing; cam means operatively connected with said spindle means and being disposed circumjacent within said ring means; fluid chamber means disposed between said ring means and said cam means;

a plurality of passage means in said spindle means; said housing means and said cam means for directing fluid to and from said fluid chamber means; check valve means disposed in said passage means in said spindle means for directing high pressure fluid to said passage means in said housing means; piston means slidably disposed in said ring means in fluid communication with said passage means in said housing means being movable radially in said ring means in response to fluid pressure in said passage means in said housing means; vane means slidably disposed in said ring means adjacent said piston means; pin and spring means operatively connecting said piston means and said vanes means for moving said vane means into said fluid chamber means when said piston means are pressurized and spring means operatively connected between said ring and said vane means radially in said ring means when said passage means are unpressurized for moving said vane means out of said fluid chambers to prevent pressure development in said fluid chambers.

US. Cl. X.R.

means and said piston means for moving said piston means 15 4 268 

